From the perspective of the accessories you mentioned I believe Beretta has more in the way of adjustable stocks, high-rib barrels and stock spacers.

I have owned both a Remington 11/87 Sporting Clays (same as the 1100) and a AL390. Both were quality guns that served well until I decided to buy over/unders. One of the best sporting shooters I know swears by his 390.

But you need to try both guns and pick the one that fits you best and feels right. Use a modified choke or tighter for trap and an improved cylinder for sporting and skeet. Get the gun set up to shoot were you want it and use it at all the games.